Filling method for product dispensing containers



July 14, 1970 L, F, .R N mu 3,520,337

FILLING METHOD FOR PRODUCT DISPENSING CONTAINERS Filed Sept. 15, 1967 2 Sheets-Sheet l INVE N TORS LEWIS F. IRLAND AMES F. FOX

July 14, 1970 1.. F. IRLAND .ET AL 3,520,331

FILLING METHOD FOR PRODUCT DISPENSING CONTAINERS Filed Sept. 13, 1967 2 Sheets-Sheet 2 INVENTORS LEWIS EIRLAND AMES F Fox 'ATTY.

United States Patent 3,520,337 FILLING METHOD FOR PRODUCT DISPENSING CONTAINERS Lewis F. Irland, Hinsdale, and James F. Fox, Chicago, Ill., assignors to Continental Can Company, Inc., New

York, N.Y., a corporation of New York Filed Sept. 13, 1967, Ser. No. 667,427 Int. Cl. B6511 1/04, 3/04 U.S. Cl. 1413 3 Claims ABSTRACT OF THE DISCLOSURE A method for filling the product in a product dispensing container of the type including a collapsible product bag disposed in the interior of the container and defining therein a propellant chamber. The bag is constructed with lengthwise spaced circumferential means imparting radial rigidity and controlling the collapsing of the container under the influence of the propellant in the propellant chamber. The spaced circumferential means form restricted volumes which communicate with the central portion of the bag. The container including the bag attached therein is rotated during the filling of the product to create a centrifugal force causing the deposited product to flow into and completely fill the restricted volume. The propellant chamber is subjected to a partial vacuum to extend the bag from its normal static length. When a vacuum is applied, the bag is filled to a level below the upper lip or top of the bag to provide a volume sufficient to accommodate the volume of the product displaced therein when the bag returns to its normal static length upon release of the vacuum.

BACKGROUND OF THE INVENTION Field of invention The present invention relates to a method for filling a product in a product dispensing container of the general type having a product bag disposed in a container body charged with a propellant, and more particularly, to a method for filling a bag having fold means for rendering the bag collapsible and defining restricted volumes into which the product is deposited.

The prior art Problems have been encountered heretofore in adequately filling containers of the fluid dispensing type incorporating a product bag. The problem is particularly acute when the bag is formed with fold means rendering the bag collapsible. The fold means define volume portions having crevices and the like into which the flow of the product is restricted. In the standard method employed heretofore the can is held stationary below the filling station and the product is deposited therein by gravity so that the flow or viscosity characteristics of the fluid is relied upon to completely fill all of the crevices of the restricted volume. Products of a high or marked viscosity would not always flow into these crevices and would form air pockets or voids. These air pockets are objectionable for the reason that under some circumstances the air entrapped therein may tend to render the product unsuitable for its intended use. Moreover, the voids reduced the product carrying capacity of the bag. Preferably, the product is filled to a maximum level which permits the dispensing valve assembly to be attached without causing spillage of the product over the top.

Difliculties have been encountered in filling the bag to this maximum level by prior filling methods without causing spillage over the open top into which the prod- 3,520,337 Patented July 14, 1970 "ice not is introduced. To eliminate this spillage, the product has been filled to a level well below the maximum so that the entire capacity of the bag was not used.

SUMMARY OF THE INVENTION By the present invention it is proposed to fill the container bag of the general type described above in a manner overcoming the difliculties encountered heretofore. This is accomplished generally by spinning or rotating the container with the bag disposed therein during the filling of the product into the bag. Rotation of the container and bag imposes a centrifugal force on the product deposited in the bag, causing the product to flow into all of the crevices of the fold means and thereby fill all of the voids.

In another aspect of the invention the collapsible bag of the heretofore described type is extended from its static length and the product filled to a predetermined level to provide an empty volume for accommodating the product which is displaced therein after the extending force is removed and the bag returns to its static length.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary front elevational view of an apparatus which may be used in practicing the method of the present invention;

FIG. 2 is an enlarged fragmentary side elevational view of the mechanism used to rotate the container into which the product is deposited;

FIG. 3 is a fragmentary elevational View partially in cross-section to show underlying details of the means used to elevate the container into engagement with a chuck of the container rotating mechanism.

FIG. 4 is a cross-sectional view of the container showing the product deposited therein and the bag extended from a normal static length by a vacuum applied through the elevating means shown in FIG. 3; and

FIG. 5 is a cross-sectional view similar to FIG. 4 but showing the bag in the normal static length thereof with the product disposed therein after the vacuum has been released.

PREFERRED EMBODIMENT Referring now to the drawings and in particular FIGS. 4 and 5, there is shown a product dispensing container 10 of the general type with which the filling method of the present invention is adapted to be used. The container 10 comprises generally a container body 11, an inner collapsible bag 12 which carries the product to be dispensed, and a propellant chamber 13 defined between the exterior of the bag 12 and the interior of the container body 11.

The container body 11 includes axially opposed top and bottom closures 14 and 16, respectively. The top closure 14- may be generally dome-shaped and formed with an axial opening 17 bounded by a rolled rim 18. The product is filled through the opening 17 into the collapsible bag 12. After the bag is filled a product dispensing valve assembly 19 is attached to the rim 18 as shown in FIG. 5.

The bottom closure plate 16 is formed with an opening or vent 21 into which there may be inserted a propellant charging valve 22. The propellant charging valve 22 is constructed to provide fluid communication between propellant chamber 13 and the container body exterior when positioned as shown in FIG. 4 and to close off communication therebetween when positioned as shown in FIG. 5. For a more detailed description of the charging valve assembly 19, reference is made to co-pending U.S. patent application Ser. No. 676,294, filed Oct. 18, 1967, and assigned to the assignee of the present invention. The vent 21 may also be closed by a grommet (not shown) which is inserted therein and through which the propellant may be inserted by a needle or the like.

The collapsible bag 12 is formed from a plastic material such as polyethylene and preferably by blow molding. The bag is constructed of a sufiicient thickness to impart shape-retaining characteristics thereto. The collapsible bag 12 includes a bottom wall or panel 23 located in vertically spaced relationship with respect to the bottom closure 16, a body wall 24, and an upper end portion 26. The upper end portion 26 includes an opening 27 bounded by a curled rim 28 which is attached to the top closure curled rim 18.

To regulate the collapsing of the bag in a manner to eliminate indiscriminate inward folding of the wall causing entrapment of the product, the body wall 24 is provided with a plurality of lengthwise spaced circumferentially extending fold bands 29 which in the form shown include panels 31. The panels 31 are arranged in substantially V-shaped configurations, each having an outer apex 30 about which the panels are foldable and an inner apex 33 which tends to radially rigidity the body wall 24. The foldable bands 29 thus form interruptions in the body wall 24 in the form of plurality of lengthwise spaced annular volumes 32 of substantially V-shaped cross-section. The annular volumes 32 communicate with an axial or central volume 34 defined by an imaginary projected volume of the inner apices 33 of the fold bands 29.

A bag formed from polyethylene by blow molding tends to told about the outer apices when removed from the mold and cooled so as to assume a normal static length less than that of the original mold length. Such shortening occurs with substantially no decrease in the axial volume of the bag. This characteristic of the bag may be utilized to achieve maximum filling thereof as will be more fully described hereinafter.

It should be evident from the foregoing that with standard gravity product filling practices may be encountered in completely filling the annular volumes 32 to the extent of the exclusion of all of the voids or air products in the crevices defined at the apices 30. These difficulties become particularly acute when the product to be dispensed is of a marked viscosity and which tends to cling on the wall structure rather than flow therealong into the crevices.

By the present invention these difficulties are obviated by rotating the container body 11 with the bag 12 attached therein during the introduction of the product to create a centrifugal force on the deposited product causing the latter to fill all of the crevices of the annular volumes 32. The apparatus for accomplishing this result may be incorporated in a substantially conventional piston-type product filling machine 36 as shown in FIGS. 1 and 2. The filling machine 36 comprises generally a conveyor feed 37 which delivers the container to a filling station 38 in timed sequence for filling of the product therein from a funnel 39. After filling of the container 10 the latter may be delivered to a propellant charging station and a dispensing valve assembly applying station, both not shown.

The container 10 is fed to the filling station 38 in the assembled condition shown in FIG. 4 with the opening 21 in the bottom closure plate 16 free of any obstruction or with the charging valve 22 positioned to permit fluid communication between the propellant chamber 13 and the container exterior for reasons which will become apparent hereinafter. The dispensing valve assembly 19 as heretofore described is attached after filling the product in the bag 12.

Located at the filling station 38 is a container spinning or rotating assembly 40 including generally a drive motor 41 which is connected to a container rotating head 42 via a speed control box 43 by way of belt and pulley drives 46 and 47. The spinning head 42 includes a tubular shaft 50 which is journaled for rotation in a bearing 48 suitably fixed to framing 49 in vertically spaced relationship above the conveyor belt 37. Holding the head 42 against vertical movement are upper and lower collars 51 and 52 respectively. The lower end of the spinning head 42 is formed to provide a chuck 53 which is engageable with the upper end of the container 10 to hold the latter for rotation therewith. The chuck 53 is formed with an axial bore 54 which is aligned with a bore 56 of the tubular shaft 50. The spinning head 42 is mounted so that the shaft bore 56 and chuck opening 54 are longitudinally aligned with a spout 57 of the product filling funnel 39.

The vertical spacing between the chuck 53 and the conveyor 37 is greater than the height of the container 10. To lift the container 10 into engagement with the chuck 53, there is provided an elevating spindle assembly 57 including a spindle 58 operatively connected to a pneumatic piston unit 59 as shown in FIG. 3. The spindle 58 may have fixed to the upper end thereof a head 61 contoured complementary to the underside of the container bottom closure 16. Seated within the head 61 so as to be concentric with the bottom closure opening 21 is an O-ring 62 which serves to form a seal for reasons which will become apparent hereinafter.

The lower end of the spindle 58 is formed with an enlarged base 63 including a counter bore 64 in which there is seated a bearing assembly 66 rotatably supporting the spindle 58 on a union 67. The union 67 is connected to a piston rod 68 of the pneumatic piston unit 59.

Extending through an axial bore 69 in the spindle 58 and head 61 is a tube 71 which is seated at its lower end in one end of a passageway 72 formed in the union 67. The passageway 72 at its other end receives a conduit or tube 73 which is flexibly connected to a source of vacuum which serves to reduce the pressure in the propellant chamber 13 for reasons more apparent hereinafter.

The upper end of the tube 71 extending through the head 61 of the spindle 58 is isolated from the lower end of the bore 69 by a sealing gasket 74 disposed within a counter-bore 76 formed in the underside of the head 61. The sealing gasket 74 is of the general type permitting free rotation of the spindle 58 and head 61 about the tube 71 which is held stationary in the union 67.

In operation the containers 10 are intermittently fed by the conveyor belt 37 to the filling station 38. When a container 10 arrives at the filling station 38 the piston unit 59 is actuated to elevate the spindle 58 and head 61 into engagement with the bottom closure 16 thereby to lift the upper end of the container into engagement with the chuck 53 of the spinning head 52. The product is deposited into the bag 12 from the funnel 39 through the axial aligned bores 54 and 56 which are aligned with the spout 57.

To achieve maximum filling of the bag 12, a vacuum may be applied to the propellant chamber 13 by way of the tubing 71 and 73. In this connection, it is to be noted that the seal formed by the O-ring 62 engaging the underside of the bottom closure 16 forms an effective chamber about the vent 21. In this manner the vacuum is applied to the propellant chamber 16 through the fluid passages provided in the valve 22. Upon the application of a vacuum in the propellant chamber 13, the bag 12 is lengthened from its normal static length to its original mold length. Such lengthening occurs by means of the panels 31 fold ing away from each other at the outer apices 30 without substantially folding about the inner apices 33, so that the cross-sectional area of the inner core volume remains substantially unchanged.

Thereafter, the motor 41 is energized to rotate the spinning head 42 and thereby the container which is in engagement with the chuck 53. Rotation of the container 10 imposes a centrifugal force on the product deposited in the bag 12 and causes the former to flow radially outward against the surfaces of the panels 31. The speed of rotation of the spinning head 42 and thereby the container 10 is regulated to achieve a centrifugal force adequate to cause the product to flow into and completely fill the crevices in the annular volumes 32 without destroying or modifying the shape of the bag 12.

Spinning of the container while filling is continued until the product is at least at a level above that of the restricted volume 32 in the fold bands 29, but under no circumstances to a level at which the product spills over the rim 18. When the spinning is stopped additional volume may be available for the product so that the product may continue to be deposited until a level is reached at which the upper section 26 of the bag 12 is filled to the extent that the dispensing valve assembly 19 may be fastened to the container body 11 without causing spillage of the product over the rim 18.

After filling to the desired level, the vacuum is released and the bag 12 tends to collapse to its normal static length causing a quantity of product proportional to the contraction of the bag 12 to be displaced into the upper portion 26 of the bag 12. Accordingly, the level to which the bag 12 is ultimately filled is maintained sufficiently below the rim 18 to provide space for accommodating the upwardly spaced product. The presence of such a space within the bag 12 prior to release of the vacuum minimizes spillage over the rim 18 while at the same time permitting filling of the bag to its maximum volume.

After filling the bag 12, the spindle 58 is lowered to again place the container 10 on the conveyor 37 for transfer to the propellant charging and dispensing valve assembly stations. To further minimize spillage during lowering of the filled container 10, the release of the vacuum may occur after the container has been lowered onto the conveyor 37.

What is claimed is:

1. The method of filling a viscous product in a product dispensing container of the type including a container body having a bottom closure, an open top which is adapted to be closed by a product dispensing valve assembly, a shape retentive collapsible bag of generally tubular cylindrical configuration of a normal static length and having a closed end and an open end, said bag being disposed in said container with said open end attached to said open top of said container and said closed end spaced from said bottom closure plate so as to define a propellant chamber within said container, said tubular cylinder including lengthwise spaced fold panel means rendering said bag controllably collapsible and defining lengthwise spaced annular volumes disposed about and communicating with an inner lengthwise extending volume; said filling method comprising depositing this product into said bag through said open end of said bag, rotating said container while this product is being deposited in said bag so as to create a centrifugal force sufficient to cause the product deposited in said bag to flow into and completely fill said annular volumes without causing distortion of said bag, discontinuing said rotation of said container when product fills said bag to a level adjacent the upper most one of said annular volumes, continuing the filling of said product into said bag to a predetermined level at which a dispensing valve assembly may be attached to the open top of said container without causing spilling.

2. The method as defined in claim 1 including the steps of extending the bag from said normal static length prior to depositing the product in said bag, filling said product into said bag to a level below said predetermined level after said rotation is discontinued to provide a space for accommodating the product, and releasing said bag from said extended length whereby the product is displaced upwardly and accommodated in said space.

3. The method as defined in claim 2 including the steps of applying a vacuum to the propellent chamber to extend said bag, and releasing said vacuum after said bag is filled to a level providing said space for accommodating the upwardly displaced product when the bag returns to said normal static length.

References Cited UNITED STATES PATENTS 3,266,212 8/1966 Monroe 141-34 HOUSTON S. BELL, JR., Primary Examiner US. Cl. X.R. 5327; 141-34 

